Yeah I picked up World of Goo as well.
Cogs is a fun puzzle game, droplitz I have too but I think I installed it once, played for 5 mins and then deleted it.
Osmos is another good indie game I've had for a while. Flow is probably the game closest to it in gameplay, or maybe the very first stage of Spore. Your a little cell and your goal is to absord smaller cells to get big, while avoiding bigger cells. Very nice soundtrack too, excellent game to play just to relax. Its not on an individual deal though, just 12 copies for $20, on for the next 3 hours. There is a demo of it on steam too.
Quote:
Enter the ambient world of Osmos: elegant, physics-based gameplay, dreamlike visuals, and a minimalist, electronic soundtrack. Your objective is to grow by absorbing other motes. Propel yourself by ejecting matter behind you. But be wise: ejecting matter also shrinks you. Relax - good things come to those who wait.